1. Field of the Invention
The present invention relates to an image processing method capable of improving the quality of data of an image digitally photographed or the like, and to an image processing apparatus, a storage medium and a program.
2. Description of the Related Art
The recent development in ink jet printing techniques allows to obtain a printed image having a better quality than a conventional printed image, by utilizing a digital camera with a large number of pixels and ink jet printing techniques.
There are, however, still some points to be improved in the quality of an image digitally photographed. Even if color matching of high fidelity in terms of numerical values is performed, color reproduction of a printed image is not always fine. It is important to determine how recorded colors are reproduced.
For example, conventional color matching for a monitor provides color reproduction within a monitor color reproduction range and does not utilize the maximum color reproduction range which a printer has inherently. Therefore, depending upon printers and media, main colors of a landscape or portrait photograph may be reproduced in colors which are not fine.
Some color is fine if it is reproduced vividly, and another color such as tint is fine if it is reproduced naturally. If all colors are modified equally, it is difficult to realize fine color reproduction. There is a tradeoff between color which is preferably made vivid and color which is preferably changed less. It is necessary to convert color by considering the relation between hue, saturation and lightness in order to reproduce fine color of high fidelity.
It is an object of the invention to print an image with vivid and fine color reproduction by setting the conversion conditions in accordance with input image data and to improve the quality of an output image, particularly landscape photographs, portrait photographs and the like, by reproducing fine main colors like original colors or emphasized colors.
In order to achieve the above object of the invention, there is provided an image processing method of changing independently component values of hue, saturation and lightness of an image represented by image data, wherein a change amount of the hue is made different at each hue angle and a change amount of the saturation is made different at each hue angle and each saturation value.
With the structure described above, a plurality of specific hues are shifted to target hues, the change quantity of saturation is set different for at hue angle and each saturation data, and the change quantity of lightness is set different at each hue angle. Accordingly, each print image can reproduce color near actual color and preferred color. Color preferred to be vivid can be made more vivid and color preferred to be suppressed can be made as it is.
Other objects and advantages of the present invention will become apparent from the following description of embodiments to follow.